Non-force reflecting method for providing tool force information to a user of a telesurgical system

• US 20050200324A1
• Filed: 03/30/2005
• Published: 09/15/2005
• Est. Priority Date: 04/07/1999
• Status: Active Grant

• Current Assignee: Intuitive Surgical Operations, Inc. (Intuitive Surgical Holdings, LLC)
• Original Assignee: Intuitive Surgical Incorporated (Intuitive Surgical Holdings, LLC)
• Inventors: Rosa, David J., Guthart, Gary S., Larkin, David Q., Prisco, Giuseppe, Mohr, Paul W.
• Granted Patent: US 8,944,070 B2
• Time in Patent Office: Days
• US Class Current: 318/568.110
• CPC Class Codes: A61B 1/00045 Display arrangement
• CPC Class Codes: A61B 1/0005 combining images e.g. side-by-side, superimposed or tiled
• CPC Class Codes: A61B 1/04 combined with photographic or television appliances
• CPC Class Codes: A61B 1/3132 for laparoscopy
• CPC Class Codes: A61B 17/00234 for minimally invasive surgery A61B17/0218, A61B17/0469, A61B17/12013, A61B17/1285, A61B17/29, A61B17/320016 take precedence
• CPC Class Codes: A61B 18/20 using laser
• CPC Class Codes: A61B 2034/107 Visualisation of planned trajectories or target regions
• CPC Class Codes: A61B 2034/305 Details of wrist mechanisms at distal ends of robotic arms
• CPC Class Codes: A61B 2090/031 torque limiting
• CPC Class Codes: A61B 2090/064 for measuring force, pressure or mechanical tension
• CPC Class Codes: A61B 2090/065 for measuring contact or contact pressure
• CPC Class Codes: A61B 2090/066 for measuring torque
• CPC Class Codes: A61B 2090/0807 Indication means
• CPC Class Codes: A61B 2090/506 using a parallelogram linkage, e.g. panthograph
• CPC Class Codes: A61B 34/20 Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis
• CPC Class Codes: A61B 34/30 Surgical robots
• CPC Class Codes: A61B 34/35 for telesurgery
• CPC Class Codes: A61B 34/37 Master-slave robots A61B34/35 takes precedence
• CPC Class Codes: A61B 34/70 Manipulators specially adapted for use in surgery
• CPC Class Codes: A61B 8/12 in body cavities or body tracts, e.g. by using catheters catheters per se A61M25/00
• CPC Class Codes: A61B 8/4218 : characterised by articulated arms
• CPC Class Codes: A61B 8/4245 : involving determining the position of the probe, e.g. with respect to an external reference frame or to the patient
• CPC Class Codes: A61B 90/36 : Image-producing devices or illumination devices not otherwise provided for
• CPC Class Codes: A61B 90/361 : Image-producing devices, e.g. surgical cameras
• CPC Class Codes: G16H 20/40 : relating to mechanical, radiation or invasive therapies, e.g. surgery, laser therapy, dialysis or acupuncture
• CPC Class Codes: G16H 40/67 : for remote operation
• CPC Class Codes: G16H 80/00 : ICT specially adapted for facilitating communication between medical practitioners or patients, e.g. for collaborative diagnosis, therapy or health monitoring

Abstract

Tool force information is provided to a user of a telesurgical system using an alternative modality other than force reflection on a master manipulator, such as providing the information on user-visible, user-audible, or haptic “buzz” or “viscosity” indicators, so as to allow expanded processing, including amplification, of the information, while not significantly affecting the stability of the telesurgical system or any closed-loop control systems in the telesurgical system.

Claims

1. A method for providing force information to a user of a telesurgical system, comprising:

determining force values associated with a tool robotically manipulated in the telesurgical system;

processing at least one of the force values to generate force information; and

providing the force information to the user of the telesurgical system in a manner so as not to significantly affect the stability of the telesurgical system.

2. The method according to claim 1, wherein the force information is provided to the user so as to warn the user if excessive force is being applied by the tool against an obstruction.

3. The method according to claim 1, wherein the telesurgical system includes a slave manipulator for manipulating the tool, and a master manipulator linked to the slave manipulator and operated by the user to control the movement of the tool.

4. The method according to claim 3, wherein the telesurgical system is configured so as to cause the slave manipulator and the master manipulator to substantially move in tandem.

5. The method according to claim 4, wherein the force information is generated so as to determine an applied force produced as the tool is pressed against an obstruction.

6. The method according to claim 5, wherein the force information is provided to the user by displaying information of the applied force on a user-visible indicator.

7. The method according to claim 6, wherein the force information is provided to the user by turning on the user-visible indicator when information of the applied force is greater than a first threshold value.

8. The method according to claim 6, wherein the force information is provided to the user by turning on a user-visible indicator when information of the applied force is greater than a first threshold value and turning off the user-visible indicator when the information of the applied force is less than a second threshold value.

9. The method according to claim 6, wherein the user-visible indicator increases in intensity as the magnitude of the applied force increases.

10. The method according to claim 6, wherein the user-visible indicator is in the form of a bar graph.

11. The method according to claim 6, wherein the telesurgical system includes a monitor having a screen visible to the user, and the user-visible indicator is a blinking icon displayed on the screen.

12. The method according to claim 5, wherein the user-visible indicator is located in the proximity of the slave manipulator.

13. The method according to claim 12, wherein the user-visible indicator is a flashing light.

14. The method according to claim 5, wherein the force information is provided to the user by turning on a user-audible indicator when information of the applied force is greater than a threshold value.

15. The method according to claim 14, wherein the user-audible indicator increases in intensity as the magnitude of the applied force increases.

16. The method according to claim 5, wherein the force information is provided to the user by activating a tactile sensation on the master manipulator when information of the static force is greater than a threshold value.

17. The method according to claim 16, wherein the tactile sensation is a haptic buzz having amplitude and frequency values so as not to substantially affect the stability of the telesurgical system.

18. The method according to claim 16, wherein the tactile sensation is a haptic viscosity added to make the master manipulator feel more sluggish to the user.

19. The method according to claim 5, wherein the force information is provided to the user by turning on a first indicator when magnitude of the applied force is greater than a first threshold value and a second indicator when the magnitude of the applied force is greater than a second threshold value.

20. A method for providing force information to a user of a telesurgical system, comprising:

determining force values associated with a slave manipulator for manipulating a tool;

using one or more of the force values in a feedback path to a master manipulator operated by a user of the telesurgical system so that the master manipulator and the slave manipulator move substantially in tandem;

processing at least one of the force values to generate force information; and

providing the force information to the user in a manner so as to have substantially no effect on the stability of a closed-loop control system including the feedback path.

21. The method according to claim 20, wherein the force values derive from strain gauge measurements taken on one or more linkages of the slave manipulator so as to indicate an applied force exerted by the tool against an obstruction.

22. The method according to claim 20, wherein the force values derive from encoder measurements taken on one or more joints of the slave manipulator so as to indicate an applied force exerted by the tool against an obstruction.

23. The method according to claim 22, wherein the generation of the force information comprises generating a Cartesian force by multiplying the torque values by an inverse transform of the Jacobian matrix.

24. The method according to claim 23, wherein the generation of the force information further comprises generating a filtered force by filtering the Cartesian force with a low pass filter to remove unwanted high frequency noise.

25. The method according to claim 24, wherein the generation of the force information further includes generating a filtered scalar force by taking the norm of the filtered force.

26. The method according to claim 25, wherein the generation of the force information further includes generating a static force by multiplying the filtered scalar force by a velocity dependent multiplier that is relatively small at high velocities and large at low velocities.

27. The method according to claim 26, wherein the velocity dependent multiplier is a natural exponential function with power of −

Av, where v is a column vector of joint velocities and A is a tunable row matrix used to tune and weight the joint velocities as desired.

32. The telesurgical system according to claim 27, wherein the force information is generated from torque contributions of the integral portions of the proportional-integral-derivative paths of one or more of the plurality of closed-loop control systems.

28. A telesurgical system comprising:

a slave manipulator having a plurality of joints for manipulating a tool;

a master manipulator linked to the slave manipulator and operated by a user to control movement of the tool;

a plurality of closed-loop control systems individually controlling movement of a corresponding one of the plurality of joints so that the slave manipulator manipulates the tool according to the operation of the master manipulator by the user; and

a force indicator coupled to individual of the plurality of closed-loop control systems to provide force information generated from torque values for motors driving the plurality of joints in a manner to the user so as not to significantly affect the stability of the telesurgical system.

29. The telesurgical system according to claim 28, wherein individual of the plurality of closed-loop control systems include a feed-forward path providing a feed-forward torque value originating from the master manipulator;

a proportional-integral-derivative path providing a feedback torque value generated using a feedback error in the closed-loop control system; and

a summing node generating a total joint torque value by summing the feed-forward torque value and the feedback torque value.

30. The telesurgical system according to claim 29, wherein the force information is generated from the total joint torque values of one or more of the plurality of closed-loop control systems.

31. The telesurgical system according to claim 29, wherein the force information is generated from the feedback torque values of one or more of the plurality of closed-loop control systems.

33. The telesurgical system according to claim 29, wherein the force information is generated from one or more external disturbance torque values estimated by an observer using one or more torque values associated with the plurality of closed-loop control systems.

34. The telesurgical system according to claim 28, wherein the force information is provided to the user so as to warn the user if excessive force is being applied by the tool against an obstruction.

35. The telesurgical system according to claim 34, wherein the force information is generated so as to determine an applied force produced as the tool is pressed against the obstruction.

36. The telesurgical system according to claim 35, wherein the force information is provided to the user by displaying information of the applied force on a user-visible indicator.

37. The telesurgical system according to claim 36, wherein the force information is provided to the user by turning on the user-visible indicator when information of the applied force is greater than a first threshold value.

38. The telesurgical system according to claim 35, wherein the force information is provided to the user by turning on a user-visible indicator when information of the applied force is greater than a first threshold value and turning off the user-visible indicator when the information of the applied force is less than a second threshold value.

39. The telesurgical system according to claim 38, wherein the user-visible indicator increases in intensity as the magnitude of the applied force increases.

40. The telesurgical system according to claim 38, wherein the user-visible indicator is in the form of a bar graph.

41. The telesurgical system according to claim 38, wherein the telesurgical system includes a monitor having a screen visible to the user, and the user-visible indicator is a blinking icon displayed on the screen.

42. The telesurgical system according to claim 38, wherein the user-visible indicator is located in the proximity of the slave manipulator.

43. The telesurgical system according to claim 42, wherein the user-visible indicator is a flashing light.

44. The telesurgical system according to claim 35, wherein the force information is provided to the user by turning on a user-audible indicator when information of the applied force is greater than a threshold value.

45. The telesurgical system according to claim 44, wherein the user-audible indicator increases in intensity as the magnitude of the applied force increases.

46. The telesurgical system according to claim 35, wherein the force information is provided to the user by activating a tactile sensation on the master manipulator when information of the applied force is greater than a threshold value.

47. The telesurgical system according to claim 46, wherein the tactile sensation is a haptic buzz having amplitude and frequency values so as not to substantially affect the stability of the telesurgical system.

48. The telesurgical system according to claim 46, wherein the tactile sensation is a haptic viscosity added to make the master manipulator feel more sluggish to the user.

49. The telesurgical system according to claim 35, wherein the force information is provided to the user by turning on a first indicator when information of the applied force is greater than a first threshold value and a second indicator when the information of the applied force is greater than a second threshold value.

50. The telesurgical system according to claim 49, wherein the first indicator is a user-visible indicator and the second indicator is a user-audible indicator.